I recently gave a shiur to visitng 10th graders. I had given this before for a Torah Tours training session. The shiur and sources are available: here. The summary/guide I wrote then is below:
This shiur deals with the question of what happened at Matan Torah. How did the Jewish people change? How did the nature of the mitzvoth change?
Feel free to open the shiur by asking people what the significance of Matan Torah with regards to the above questions.
The shiur begins with a well-known contradiction in Rambam. Rambam in his description of the development of mitzvoth in Hilchot Melachim (1) seems to claim that mitzvoth developed historically. There were the mitzvoth that existed before Matan Torah, and Matan Torah just added many more.
In sources (3) Rambam presents a different perspective. As background, source (2) records a dispute between Rabbi Yehudah and the Chachamim as to whether the prohibition of Gid HaNasheh applies only to kosher animals, or even to non-kosher animals. The discussion in the Gemara revolves around a complicated question of issur hal al issur or not. The primary point for our discussion is the argument that Rabbi Yehudah makes in the Mishnah, namely that it must be that the prohibition applies to non-kosher animals, as the prohibition began at the time of Yaakov, when there was no such things as kosher and non-kosher. The Chachamim respond that the prohibition in fact was only commanded after Matan Torah. From this comment, Rambam argues that all mitzvoth are only obligatory because of Matan Torah, and as far as Jews are concerned, pre-Matan Torah history is irrelevant. This goes against his position in Melakhim.
This question seems to relate to the question of whether Jews are “Non-Jews+” or entirely different types of people. For this question, I have included a dispute between Rabbi Yisrael Gustman and Minchat Chinuch. As background, one must know that it is a dispute in the Talmud as to whether blind people are obligated in mitzvoth or not (see for example Kiddushin 31a and Bava Kama 86b-87a). This dispute carries through to the Rishonim and Achronim as well. There are discussions among the Rishonim and Achronim as to whether the position that exempts blind people from mitzvoth is absolute or not. Within this context, R. Gustman argues that if one thinks that the exemption of blind people is absolute, this will include an exemption from the seven mitzvoth benei Noach as well. His argument is that even if blind non-Jews would be obligated, Jews are totally different from non-Jews and do not maintain any of their status or obligations as non-Jews. Minchat Chinuch, on the other hand, argues that non-Jews are obligated in their mitzvoth even when they are blind, and they have no specific verse exempting them. Therefore, he assumes that as Jews are non-Jews with added holiness, a blind Jew will at least be obligated in the mitzvoth that non-Jews are obligated in.
At this point, feel free to open up for discussion about the philosophical implication of this position. You can discuss different perspectives that emerge from the Mishnah in Avot (3:18) that clearly says that all people were created in the image of God, and Jews are also the children of God, with some commentaries still explaining that only Jews are created in the image of God. For some issues that come up, see my article here: http://www.kolhamevaser.com/2010/10/how-are-you-different-from-an-animal-and-why-should-you-carea-halakhic-biological-taxonomy/.
If you at this point you feel like adding lomdus, you can point out that this dispute relates to a machloket Rishonim and Achronim as to whether there can be a “partial Jew,” a category created by some to explain the phenomena of Ger Toshav. The position of Rabbi Gustman, who sees Jews and non-Jews and wholly different, leads him to believe that a Ger Toshav must be a partial Jew, because otherwise he would not be able to be obligated in any mitzvoth. Others, who think that the mitzvoth of the Torah built on previous mitzvoth, can fathom a category of a non-Jew increasing his own mitzvoth.
At this point, either open up the floor for discussion about the problem in Rambam raised above, or provide your own explanation. My explanation, which you are free to take or leave, is that the actions stayed the same, but the people changed. Thus, the actions took on a new context, even though they were technically the same as they were before. As a mashal – while people can go out to eat when they are dating and they can go out to eat when they are married, it is clear that valence of that act is not the same both times. The changed relationship makes the same action even more intimate. So to with Matan Torah, while one level, the mitzvoth could be the same as they were before Matan Torah, the fact that the Jews became the spouse of God, as Chazal say, מורשה קהלת יעקב should be read as מאורסה – made the same actions totally different.
This leads, if you have a time to the famous Midrash in (6). In this Midrash, the nations of the world reject the Torah because they cannot keep the mitzvoth included in it. However, a problem raised by many is that mitzvoth they claim that they cannot keep all fall into the category of the sheva mitzvoth, which they are already obligated in. If so, what are they responding? Many formulations of the same answer have been given. The claim is that while both Jews and non-Jews cannot kill, the meaning of this for Jews is different. Non-Jews cannot engage in murder, Jews cannot be murderers – they have to change who they are. Furthermore, more things are considered murder, such as embarrassing others (Sotah 10b, Bava Metziah 59a). I would suggest that this higher standard is due to the new relationship with Hashem, that takes the same actions and changes their meaning. This point is indicated in the expanded read of the Aseret HaDibrot in Targum Yonatan (8).
For a suggestion as to how to read this Midrash, see http://adderabbi.blogspot.ca/2005/06/alternative-reading-of-well-known.html.